CA1054984A

CA1054984A - Dispensing device

Info

Publication number: CA1054984A
Application number: CA258,248A
Authority: CA
Inventors: Rustom K. Gamadia
Original assignee: Unilever PLC
Current assignee: Unilever PLC
Priority date: 1975-08-01
Filing date: 1976-07-30
Publication date: 1979-05-22
Also published as: JPS5218204A; FR2319788A1; SE7608649L; AT358981B; BR7604906A; NO762666L; ZA764564B; DE2633723A1; AU1637176A; FI762126A; ATA559876A; DK346776A; NZ181578A; GB1551038A; ES450331A1; FR2319788B1; BE844569A; NL7608562A; AR210895A1; JPS5720859B2

Abstract

ABSTRACT OF THE DISCLOSURE
A finger-operable pump for dispensing liquids comprises a feed chamber for receiving a liquid product from an external supply via a feed valve, a discharge chamber communicating with the feed chamber from which the product is discharged to atmoshpere, and a discharge valve having a displaceable member which is displaced to open the valve only after the liquid under increasing hydraulic pressure has passed from the feed chamber to :
the discharge chamber.

Description

Ihe invention relates to a pump for dispensing liquids, gels or foam~ 7 hereinafter referred to as "liquids".
In a conventional pressurised pack dispensing device, such as an aerosol can9 a liquid produc-t to be dispensed is normally stored under positive pressure in admi~ture with a liquefied gaseous propellant. When the product is dispensed from this type of device, i-t is there~ore usually accompanied by propellant in liquid or gaseolls form which can assist in atomising the product, but which can in other respects be detrimen-tal to the product and be disliked by the consumer.
The use o~ a li~uefied gas propellant in particular can furthermore create a problem for the ~ormulator, for example because of phase separation in the pack or other incompatability with the ingredients of the product. The use of a liquefied gas propellant does, furthermore, add -to the cost of the product. Accordingly, it is apparent that it would be beneficial both to the manufacturer and to the consumer i~
liquid products of the type normally dispen~ed in aerosol form from pressuri~ed packs could be dlspensed ln a similar manner with the aid of a suitable pump without the need to employ any liquefied gaseous propellant.
Furthermore, with the current annual world usage o~
propellant based products running at several thousand million units, the demand for pump products as an alternative to propellant based products is likely to be very substantial.

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Many attempts have in the past been made to develop efficient a~d effective finger operable pumps for dispensing propellant-free liquid products in aerosol form, as an alternative to the use o~ conventional propellant-based pressurised pack dispensing devices. Although some o~
these pumps are theoretically capable of deliveriny the product in a predictable and uni~orm spray pattern irrespective o~ the finger force applied to the actua-tor button, in practice it has proved impossible to manufacture them economically on a mass production scale using the construction materials available today such a~ are employed in the manu~acture o~ aerosol valves. In particular, it has proved exceedingly difficult to construct the pump described in the above Netherlands Patent Application such that the radial passageways through which liquid product is dispensed line up correctly when the pu~p is actuated. Furthermore, the O ring of the piston which traverses the cylinder at the point where the cylinder wall is interrupted by a radial passageway, suffers from excessive uneven wear from reciprocal travel, with the .result that leakage past this O ring can occur after prolonged U9 e.
It will be appreciated that in order to complement or replace conventional propellant-based aerosols, it is necessary to provide an inexpensive, e~ficient and effec-tive pump devoid of the above mentioned disadvantages that will enable pump sprayahle products to be marketed at a price competitive with -that of corresponding aerosol products. Accordingly, the .,,~,~
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use of plastics materials for moulding man~ of the constituen-t parts of such a pump is desirable where there is a need to produce the millions of pump units required to meet the anticipated demand.
We have now developed a finger operated pump for dispensing liquids which employs an entirely new mechanism for triggering the discharge o~ a liquid product, which does not rely on the critical tolerances and high precision neceissitated by our earlier design as described in the above Netherlancls patent application, and which has proved to be ideally suited for manufacture on a mass production scale from moulded plastics materials. We should however s-tipulate that the invention i~ not limited to a pump made largely from plastics materials, since certain other materials, such as metals, could be used as an alternative.
It is therefore an object of the invention to provide a finger-operable pump which is capable of delivery with a positive action a liquid product in a predictable and uniform spray pattern, irrespective of differences in the finger force applied to the actuator mechanism of the pump, over an extended period of u~e.
It is also an object o~ the invention to provide a finger-operable pump h~ving a feed chamber of variable volume which is capable of repeatedly delivering equal volumes of a liquid product.

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. . , ,, ' ''.' i ' ' " ' ~, '~,:'i', , ',,: ., . ,,; ' ' ' It is a further object of the invention to provide a finger-operable pump in which the pressure at which liquid product i9 dispensed is always substantially the same, irrespective of the ~inger force applied to the actuator mecharlism and the rate at which that mec~lanis~ ~s operated.
It is yet a fur,ther object of the invention to provide a ~inger-operable pump in which when finger force is applied to~~the ac~uator ~ecllanism, de~ivery of the liquid produc-t is delayed until a predetermined hydraulic pressure has been built up within the pump9 or until its actuator mechanism has been displaced by a predetermined distance.
~ It is yet a further object of the invention -to provide a finger-operable pump in which means is provided for positively triggering the delivery of a liquid product in atomised form without interruption of the adjacent surfaces of the feed chamber within the pump which define the outline of that chamber.
According to the invention, there is provided a finger o'perable pump for dispensing liquids comprising a feed chamber having a finger displaceable member displaceable ~rom a rest position to reduce the volume of the feed chamber and increase hydraulic pressure therein, and a ~eed valve to permit.entry of liquid into the feed chamber ~rom an external supply, the ~eed valve being closed when the displaceable ' member is moved to reduce the volume of the feed chamber;

a discharge chamber in communication with the ~eed chamber, resilient means co-opera-ting with the discharge chamber to store energy derived ~rom an increase in hydraulic pressure therein as the volume of the feed chamber is reduced; and a discharge valve in the finger displaceable member having a valve member movable with respect to -the displaceable member to open the discharge valve.
The pump essentially consists o-f a feed chamber having a finger displaceable member, displaceable from a rest position to reduce -the volume of the feed chamber and increase hydraulic pressure therein.
According to one embodiment of the invention, the feed chamber is a cylinder and the finger displaceable member is a piston slidably positioned in the cylinder, the piston being fitted with a stem carrying an actuator button for finger displacement. In this embodiment, the walls of the cylinder are preferably without interruption along that part traversed by the piston so as to avoid ~meven wear of the sealing edge of the piston during reciprocal movement.
According to another e~bodlment of the invention, the feed chamber is a bellows unit having an integral or sealably ~itted finger-displaceable wall, displacement of which from-a rest position will reduce the volume o~ the bellows.
The finger~di~placeable wall can convenientl~ be fitted wi-th a stem carrying an actuator button for finger displacement.

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Associated with the pump i9 a feed valve which is preferably pressure actuable and which i9 arranged to permi-t entry o~ a liquid product to -the ~eed chamber from an external supply, for example from the can, bottle or other container to which the pump is attached. The valve can, for example, be arranged to open to admit liquid product to the feed chamber during a filling stroke when the pressure in the ~eed chamber falls below that in the container.
The feed valve can for example be a non-return ball valve. Alternatively, it can be a check or flap valve which operates as a non-return valve. Such valves can be provided with a coil spring or other resilient means such as a flexible plastic insert to biase them to the normally closed position.
The feed valve is normally closed when the finger-displaceable member is moved to reduce the volume of the feed chamber and opens to permit the passage of liquid product to the feed c~hamber when the finger displaceable member i9 moved to increase the volume of the feed chamber.
The pump is also provided with a discharge chamber which can for example be positioned co-axially with respect to the feed chamber. The discharge chamber is preferably annular in cross section and can conveniently surround the feed chamber.
The feed chamber and the discharge chamber are in communication with each other so that liquid product can pass 5~
between them. At least one passageway can provide communication between the chambers, the passageway providing a conduit to enable liquid product to pass from the feed chamher to the discharge chamber when the hydraulic pressure in the feed chamber is increased. This passageway can also function to ensure that the liquid product is thoroughly mixed withln -the pump before it i9 discharged to atmosphere, by virtue of the shear to which it is subjected as it passes rapidly from -the feed chamber $o the discharge chamber.
This is particularly valuable where -the liquid product to be dispensed is multiphase or in the form of a shearable gel.
A resilient means, for eæample a ~pring, is positioned co-operably with the discharge chamber. ~his resilient means is capable of storing energy generated by the increase in hydraulic pressure which results from a reduction in the volume of the feed chamber following displacement of the finger displaceable member of the feed chamber, and the transfer of liquid from the feed chamber to the discharge chamber. When the resilient means is a spring, it can conveniently be accommodated within the di~lcharge chamber or co-axia~ly with it.
According to one embodiment of the invention, the .
discharge chamber houses at least one plunger which i~s slidably loca-ted therein in a sealable manner, together with a ispring for storing energy which functions as the resi]ient means. The , , , . . ~ .

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plunger is resilien-tly Loaded by the spring and is arranged to move agai~st the force exerted by the spring when liquid product passes into the discharge chamber and hydraulic pressure therein on the side remote from the spring increases.
In a modification of this embodimen~t a second plunger is provided in the discharge chamber toge-ther with its own spring ~or storing energy which toge-ther with the first spring functions as the resilient means. In this modification, the two plungers with their respective springs can be mounted in the opposite ends of the discharge chamber so that they are arranged to move apart against their respective springs when hydraulic pressure in the discharge chamber between the plungers increases, and move -toward each other when hydraulic pressure in this chamber decreases.
According to another embodiment of the invention, the discharge chamber comprises a bellows unit, which is arranged to expand under increasing hydraulic pres~sure while receiving liquid product from the feed chamber and to contact while discharging liquid product from the pump. ~his bellows is resiliently loaded by one or more springs (the resilien-t means) which function to ~-tore energy while the hydraulic pres~sure increases until the release point is reached when the product is discharged.
~ discharge valve carried by the finger-displaceable member and having a valve member movable l~ith respect to the _ 9 ~

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finger-displaceable member is provided for positively triggering the discharge of liquid product, usually when the finger displaceable member has moved a predetermined distance or when hydraulic pressure within the feed chamber has reached a maximum. The opening of the discharge valve also releases the energy stored in the resilient means which then forces the liquicl product from the discharge chamber u~ually to atmosphere.
The discharge valve is preferably a mechanically actuable valve opening through the ~inger displaceable member of the feed chamber, which is so positioned as to be mechanically actuated by relative movement of a valve member when the volume of the feed chamber approaches its minimum value.
Thus, according to a preferred embodiment of the invention, the discharge valve is a spigot valve seated within the finger displaceable member. The provision of this spigot valve has been found to eliminate many o~ the problems of leakage around the pis-ton, where -the feed chamber is defined by a piston and cylinder, and it also provides a smoother pumping action and more positive actuation than ha~ hitherto been possible with the other pumps. The invention is however not restricted to the inclusion of the spigot valve since other valve means can be employed for releasing stored energy by rela-tive movement of a valve member, after the . . ~

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finger displaceable member of the feed chamber has been displaced by a prede-termined distance relative to the feed chamber itself.
It is also possible for the discharge valve to be pressure rather than mechanically actuable, so that it will open only whe~ hydraulic pressure within the pump-has increased to a predetermined valueO
A discharge conduit can be provided to enable the discharge chamber to communicate with the atmosphere exterior to the pump, so that liquid product can be discharged when the pump is actuated. Preferably, the discharge conduit forms the hollow portion of the stem connecting the finger displaceable member and the usual actuator button from which the liquid product is discharged to atmosphere, for example as a finely-divided spray.
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It is a preferred feature of the invention that where the finger-displaceable member and the feed chamber comprise a piston and cylinder, then the sealing edge of the piston should form a liquid tight seal with the cylinder wall, at least until the discharge valve i9 opened. This is to ensure -that the liquid product under the influence of increasing hydraulic pressure during displacement of the piston from the rest position does not prematurely leak past this seal before the discharge valve opens to release the liquid product to atmosphere. As soon as this valve opens and the liquid product is dispensed, there is then rlo need for the seal -- 11 -- / . . .

between the pi~ton ancl cylincler to be maintained, al-though we have found that to avoid uneven wear and stress on the par-ts maintaining this seal, it i9 preferable that this seal is also maintained af-ter the discharge valve has opened. Efficient dependable trouble-~ree operation of the pump over an extended period of use is with this arrangement more likely to be the experience of the user than with a pump in which the sealing edge of the piston exib~ from or in some way separates from its cylinder, for example at the end o~ a downstroke, each time the pump is actuated.
In an alternative arrangement where the feed chamber and its finger-displaceable member comprise a bellows unit, it is similarly important to ensure that leakage does not occur where the corrugated side wall of the bellows joins an end wall which forms the finger-displaceable member.
Preferably, the bellows unit with its end wall are integral and can for example conveniently be moulded as a single unit in suitable plastics material.

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These as well as other advantages of the pump will be more fully understood with reference to the accompanying diagrammatic drawings o~ which:
Figure 1 i9 a section through a pump in accordance with the invention, the pump being shown at the commencemen-t o~ a downstroke;
Figure 2 is a section through a pump of the type shown in Figure 1 at the end of a downstroke;
Figure 3 is a section through a pump, in principle, similar to that shown in Figure 1 at the commencement o~ a downstroke, but showing certain refinements which facilitate its construction and as~embly and which improve its operation;
Figure 4 is a section through a p~p of the type shown in Figure 3 at the end of a downstroke;
Figure 5 is an enlarged section of part of the pump of the type illustrated in Figures 1 to 4, showing a spigot valve and axial piston in enlarged proportions;
Figure 6 is a section through a pump dispenser similar to that illustrated in Figure l.in a non-actua-ting condition at the commencement of a downstroke, except that the plunger is in a ~ixed relationship with the apertured pla-te, the outer body being free to move when the pump is actuated;
. Figure 7 is a section through a pump dispenser of the type shown in Figure 6 in an actuating condition at the end o~ -the downstroke;

Figure 8 is a section through a pump similar to that illustra-ted in Figure 1, except -that the axial piston and plunger have been replaced by bello~qs. The pump in Figure 8 i9 shown in a non-ac-tuating condition;
Figure 9 is a section through a pump similar to that illustrated in Figure 8 in an actuating condition;
Figure 10 is a section through a pump similar to tha-t illustrated in Figure 8, except -tha-t the bellows replacing the plunger is of a di~erent design. The pump in Figure 10 is shown in a non-actuating condition;
Figure 11 is a sec-tion through a pump similar to that illustrated in Figure 10 in an actuating condition;
Figure 12 i9 a section through a pump similar to that illustrated in Figure 1, except that the axial plunger has been replaced by bellows. The pump in Figure 12 is shown ln a non-actuating condition;
Figure 13 is a section through a pump ~imilar to that illustrated in Figure 12 in an actuating condition;
Figure 14 is a section through a pump similar to that illustrated in Figure 1, except that the axial piston has been replaced by bellows. ~he pump in Figure 14 is shown in a non-actuating condition;
Figure 15 is a section through a pump similar to that illus-trated in Figure 14 in an actuating condition;

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Figure 16 is a section through a pump simllar to that illustrated in Figure 1, except that a second plunger and spring have been added within the axial discharge chamber.
The pump in Figure 16 is shown in a non-actuating condition at the commencement of a do~nstroke;
Figure 1~ is a section through a pump of the -type shown in Figure 16 in an actuating condition at -the termination o~ a downstroke;
It will be noted that in each of the embodiments illustrated in Figures 1 to 17, the discharge ~hamber is annular ln form and is accordinqly referred to~
in the following description as an annular discharge chamber.
- According to a first embodiment illustrated in Figures 1 and 2 of the drawings, the p~p oonsists of a cylindrical outer body 10 closed at one end by an apertured plate 11, and at -the other end by a flange 12 o~ pump cylinder 13, which is located co-axially within the outer body lOo A finger-displaceable axial piston 14 is slidably located in bore 15 of pump cylinder 13, the upper end of this piston, i.e. the piston stem9 passing through the apertured plate 11. The piston 14 and the cylinder 13 together define the ieed chamber having a inger-displaeeable member. The . .
~tem o~ the piston 14 is hollow throughout its length, the upper end ag shown in Figure~ 1 and 2 of the drawings forming ~ o ~ 9~
a discharge outlet 16~ The lol~er end ~f piston 14 is a snug fit within the bore 15 of the pump cylinder 13. An iO' ring 51 fitted arol~d the piston 14 just above the lower en~ further ensures that the piston 14 provides a liqui~
tight fit within the bore 15. Fitted axially'within the lower end o~ piston 14 is a spigot valve 4~ with associated seating ~3, the spigot valve heing biased towards the seating by spring 4~ housed within the piston 14.
The spigot valve constitutes the discharge valve having a valve member ~i.e. the spigot valve 42) moveable with respect to the displaceable member.
The stalk ~5 of spigot valve 42 normally extends below the lower end of piston 14 as shown in the Figures 1 and 2 of the drawings, the stal~ being in axial alignment with an associated upper end 46 of spacer 20. The upper end of discharge outlet 16 in piston 14 can be closed by an actuator button (not shown).
The pump cylinder 13 also houses a piston return spring 18 abutting lower end 19 of piston 1~ and upper face of apertured spacer 20. This spring b~ases the piston upwards as shown in the drawings so that piston shoulder 21 abuts the apertured plate 11 when the pump is in the non-actuating condition as shown in Figure 2. ~he spacer 20 separates the pump cylinder 13 ~rom a non-return pressure aotuable feed valve assembly 22.

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The pump cylinder 13 sho~n in Figures 1 and 2 i9 provided with at least one radial passageway 31 opening into annular discharge chamber 32 between ou-ter body 10 and pump cylinder 13. It is this radial passageway, communicating the feed chamber with the discharge chamber, which provides a conduit for liquid product to pass ~rom the feed chamber (i.e.
cylinder 13) to the annular discharge chamber 32 when hydraulic pressure in the feed chamber increases.
~ The annular discharge chamber 32 houses an annular plunger 33 with seals 35 which is biased by a spring 36 (the resilient means) and which can slide within the annular discharge chamber.
The wall of outer body 10 and that of pump cylinder 13 are both perforated with corresponding breathing channels 39 and 40, which communicate with each other via the upper par-t 41 of annular discharge chamber 32. This upper part 41 also ` houses the spring 36.
In use, the pump as illus~trated in Figures 1 and 2 of the drawings is applied to the top of a container of a liquid product so that the non-re~urn pressure actuable feed valve assembly is in contact with the product, i~ necessary via a dip-tube (not shown).
At the firs-t downs-tro~e of pis~ton 14 toward the pressure actuable feed valve 22, the pis-ton return spring 18 is compressed and wh0n stalk 45 of spigot valve 42 is displaced - 17 - /~o .

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by contact with upper end 46 of spacer 20, air in bore 15 is bled via radial passageways 31, annular discharge chamber 32 to atmosphere. l~len piston 14 is released, liquid product is drawn up -through th~ feed valve assembly 22 into cylinder S bore 15. I'his is a primin~ operation and the p~p is now ready for use.
At the second or subsequent downstroke of the piston 14, hydrauIic pressure within cylinder bore 15 increases and liquid product is thereby caused to flow via radial passageways 31 and annular discharge chamber 32 to annular plunger 33.
Further increase in hydraulic pressure on this liquid displaces the annular plunger 33 against spring 36, so that liquid flows into the annular discharge chamber 32. As plunger 33 moves, the volume of the annular discharge chamber 32 increases and accummulating energy is stored in spring 36 as it is compressed.
As pressure increases still further displacement of annular plunger 33 continues in order to accommodate liquid, until the stalk 45 of spigot valve 42 contacts the upper end 46 of spacer 20. Continuation of the downs-troke beyond this point unseats the spigot valve 42 and~its displacement against bias of spring 44 allo~s liquid to pass from the annular discharge chamber 32 ~ia radial passageways 31, cylinder bore 15 and past seating 43 to ~ischarge outlet 16 in piston 14 and finally to atmosphere via actuator button (not shown3.

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As liquid is discharged, decompression of spring 36 forces annular plunger 33 downwards to the rast position. The annular discharge chamber 32 is ~inally sealed to atmosphere when finger pressure on the pump is released, piston 14 returning upwards to the rest position under decompression of piston return spring 18. Simultaneously, more liquid product i9 drawn into the cylinder bore 15 via the ~eed valve assembly 22 and the dischar~e and filling cycle can then be repeated.
The breathing channels 39 and 40 ensure that the gas pressure within the container to which the pump is fitted is maintained at atmospheric pressure.
It will be noted that at no time during the operation of the pump does the piston leave ~he confines of the bore of the cylinder, thus reducing to an absolute minimum wear on the single 0 ring 51 which seals the piston 14 within the cylinder bore 15; also the 0 ring 51 seals piston 14 to the pump cylinder 13 both before and a~ter the spigot valve operates to release liquid pressure to atmosphere.
According to the second embodiment of the invention as illustrated in Figures 3 and 9 o~ the drawings, the pump consists of a cylindrical outer body 10 closed at its upper end by an apertured end plate 11 and conically tapered at its lol~er end lOa to house pump cylinder 13, spacer 20 and non-return valve assembly 22.

' A finger displaceable axial piston 19 is slidably located in bore 15 within pump cylinder 13, the stem of the piston passing through the apertured plate 11. An axial feed plunger 52a with sealing lip 53 is snap fitted to the lower end of axial piston 14 via annular t,ang 5~. An annular slot 61 and cylindrical slc-t 62 in the axial feed plunger 52a together ensure that the lip 53 is flexibly applied in a sealable fashion to the bore 15 of pump cylinder 13. By this means a per~ect seal between cylinder and plunger can be obtained wi-th minimum friction and minimum wear of the sealing lip 53 when in use. The piston 14 with its feed plunger 52a together constitute the finger displaceable member, and the feed plunger 52a and cylinder 13 together define the feed chamber.
Fitted within the lower hollow end of pis-ton 14 and within axial feed plunger 52a i9 a spigot valve 42 with associated seating 43, the spigot valve being biased towards the seating by spring 44 also housed within the lower end of piston 14. The ~pigot valve is the discharge valve having a moveable valve member.
The spigot valve and axial feed pl~mger assembly is shown in greater detail in Figure 5 of the drawings.
The ~talk 45 of spigot valve 42 normally extends below the lower end of axial feed plunger 52a as shown in the drawings, the ~talk being in axial alignment with the upper end 46 of _ 20 - I

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spacer 20. The upper end of dischar~e outlet 16 in piston l~
can be closed by an actuator button (not shown).
The pump cylinder 13 also houses a piston return s~pring 18 abutting lower end 19 o-f piston 1~ and apertured spacer 20. This spring biases -the piston upwards as shown in Figure 3 of the drawings, so that piston shoulder 21 forms a seal against washer 67 mounted within apertured end plate 11 when the pump is in the non-actuating condition. The spacer 20 separates the pump cylinder 13 from a non-return feed valve assembly 22.
- The pump cylinder 13 shown in Fugures 3 and 4 of the drawings i9 provided with radial passageways 31 (only one of whiGh i.9 shown) communicating the bore 15 of pump cylinder 13 with an annular discharge chamber 32 de~ined by the outer body lS 10 and the pump oylinder 13. The annular discharge chamber 32 houses an annular plunger 33 with sealing lips 55 which is biased by a spring 36 (the resilient means). This spring is housed within annular cavity 41 also defined by outer body 10 and pump cylinder 13. This annular cavity thus forms an e~ten3ion of the annular discharge chamber.
The apertured plate 11 is provided with annular lips 56 and 57 for facilitating a snap-fit with annular lip S8 of the neck 60 of a container (not shown) and annular lip 59 o~ the ou-ter body 10 respectively. It will be noted that the ~our annular lips 56,58,57 and S9 toge-ther co-operated to form I

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' ,. ~ ' ,, , ', '' ' a secure snap-fit of -the three parts constituted by the neck 60 of the container, the apertured plate 11 and the outer body 10.
~he annular lips 57 and 59 are interrupted at one point (not shown) to provide communication between the inside of the container -to which the pump i9 ~itted and the atmosphere via labarynthine passageway 63 defined by apertured plate 11, outer body 10 and outer wall of piston 14 above the axia] feed plunger 52a. This passageway 63 is sealed by ela~tomeric washer 67 when the pump is in a non-actuating condition as shown in Figure 3 of the drawingsO
Figure 5 shows the arrangement of spigot valve and piston in greater detail.
In use, the pump as illustrated in Figures 3 and of the drawings operates in a manner similar to that desc-ribed for the pump illustrated in Figures 1 and 2 of the drawings.
The component parts of the pump illustrated in Figures 3,4 and 5 of the drawings except for the springs can be moulded from flexible plas-tics material. For example, the apertured plate 11, outer body 10, lOa, pump cylinder 13 and piston 14 can each be moulded from high density poly-propylene while the axial plunger 52, annular plunger 33 and spacer 20 can be-moulded from low density polyethylene. By using materials such as these, manufacture and assembly of the component parts on mass production scale can be facilitated.

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According to the third embodiment illustrated in Figures 6 and 7 o~ the drawings, the pump consists of a cylindrical outer body 10 mounted between a ~irst apertured plate 11 at the upper end and a second apertured plate 12 at the lower end. Integral with the ~irst apertured pla-te 11 and axially dependant from it is pump cylinder 13 together with surrounding cylindrical guide member 48.
The cylindrical outer body 10 is integral with the second apertured plate 12 and together they are arranged to slide axially over the cylindrical guide member 48 and pump crl inder 13.
A finger displaceable axial piston 14 is slidably located in bore 15 within the pump cylinder 13, the stem of the piston passing through the first apertured plate 11.
-15 The piston 14 and the cylinder 13 together defining the feed chamber having a finger displaceable member. The stem of the piston as shown in Figures 6 and 7 of the drawings is hollow and forms a discharge outlet 16. Fitted within the lower hollow end o~ piston 14 i~ a spigot valve 42 with associated seating 43~ the spigot valve being bia~ed towards the seating by spring 44 housed within the lower end of pis-ton 14. The spigot valve is the discharge valve having a moveable member.
The stalk 45 of spigot valve 42 normally extends below the lower end of pis-ton 14 as shown in Figure 6 o~ the drawings, the stalk being in axial alignment with upper end 46 of spacer 20.

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The upper end of di~charge outlet 16 in piston 14 can be closed by an actuator button (not shown).
The pump cylinder 13 also houses a piston return spring 18 abutting lower end 19 of piston 14 and spacer 20. This spring biases the piston upwards as shown in the drawings so that piston shoulder 21 abu-ts first apertured plate 11 when the pump is in the non-actuating condition as shown in Figure 6. The spacer 20 separates the pump cylinder 13 from the non-return feed valve assembly 22.
The pump cylinder 13 shown in Figures 6 and 7 of the drawings is provided with at least one radial passageway 31 opening into annular discharge chamber 32 between outer body 10 together with integral second aper-tured plate 12 and pump cylinder 13.
It is this radial passageway, communicating the feed chamber with the discharge chamber, which provides a conduit for liquid product to pass from the feed chamber to the annular discharge chamber 32 when hydraulic pressure in -the feed chamber increases.
The annular discharge chamber 32 houses an annular piqton 33, with seals 35 which is fixed in rela-tion to pump cylinder 13 and cylindrical guide member 48.
The cylindrical guide member 48 and the outer body 10 each have a flange 49 and 50 which are biased apart by a spring 36 (the resilient means). ~his spring is thus housed in - 2~

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annular cavity 41 defined by the outer body 10, cylindrical guide member 48 and their respective flanges 50 and 49.
This annular cavity 41 thus forms an extension of the annular discharge chamber 32.
The wall of outer body 10 and that of pump cylinder 13 are both perforated with corresponding breathing channels 39 and 40 which communicate via the annular cavity 41.
In use, the pump illustrated in Figures 6 and 7 of the drawings i9 applied to the top of a container of liquid product 90 that the non-return feed valve assembly is in contact with that product 9 if necessary via a dip-tube (not shown).
At the first downstroke of piston 14, the piston return spring 18 is compressed and air in bore 15 is temporarily ~orced via radial passageways 31 into annular chamber 32, and is then released to atmosphere, when stalk 45 o~ spigot valve 42 is displaced by contact with upper end 46 of spacer 20. When piston 14 is released, the spigot valve closes and liquid is drawn up through non~return feed ~alve assembly 22 into cylinder bore 15. This is a priming operation and the pump dispenser is now ready for use~
At the second downstroke oY the piston 14, the hydraulic pressuIe on liquid within cylinder bore 15 .Lncreases and liquid is thereby caused -to ~low via radial passageways 31 into annular discharge chamber 32. Unlike the embodiments ' ' ~ . ~:' .:

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illus-trated in Figures 1 and 2, the annular piston 33 o~
the embodiment illustrated in Figures 6 and 7 o~ the drawings is fixed in relation to pump cylinder 13 and there~ore further increase in pressure on this liquid displaces outer body 10 together with integral second apertured plate 12 slidably downwards in relation to the pump cylinder 13 thereby to accommodate the liquid in -the increased volume of annular discharge chamber 32. As the volume of this chamber increases, accumulating energy is stored in spring 36 as it is compressed with annular cavity 91.
As hydraulic pressure increases still further, displacement o~ outer body 10 and second apertured plate 12 continues to increase in order to accommodate more liquid, until stalk 45 of spigot valve ~2 contacts the upper end 46 of spacer 20. Continuation of the downstroke beyond this point unseats the spigot valve 42 and its displacement agains-t bias of spring ~ allows liquid to pass from the annular chamber 32 via radial passageways 31, cylinder bore 15 and past seating ~3, to discharge outlet 16 in piston 14 and finally to atmosphere via actuator button (not shown). The discharge attitude of the pump dispenser is shown in ~igure of the drawings.
As liquid is discharged, decompression of spring 36 biases apart flanges ~9 and 50 so that outer body 10 together with second apertured plate 11 return slidably to the rest - 26 ~ o ,, , :: . , . ' ' ~
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position as ~hown in Figure 6 of the drawings. The annular discharge chamber 32 is finally sealed when finger pressure on the pump dispenser is released, the spigot valve 42 closing and the piston 14 returning to the rest position under decompression of piston return spring 18. Simultaneously, more liquid product is drawn into the cylinder bore 15 via non-return f'eed valve assembly 22 and the discharge and filling cycle can then be repeated.
It will be noted that the relationship between the sealing action of the piston on the cylinder and the operation of the spigot val~e is similar to tha-t described with reference to Figures 1 to 5.
According to the fourth embodiment of the invention as illustrated in F'igure 8 and 9 of the drawings, the pump consists of a cylindrical ou-ter body 10 closed at the upper end by an apertured plate 11, and at the lower end by a flange 12 of pump cylinder 13, which i9 located concentrically within the outer body 10.
A finger displaceable axial piston 1~ is slidably located in a bore 15 within the pump cylinder 13, the piston passing through the apertured plate 11. ~he stem of the pisto~ 14 is hollow throughout its length, the upper end as shown in the drawings forming a discharge outlet 16.
An axial ~eed plunger 52 is fit-ted to the lower end o-f piston 1~; both a~ial plunger and piston are loosely ' ' '', ; , :
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slidable within the bore 15 of the p~mp cylinder and do not form a snug liquid tight fit as do the corresponding part~
of the pump as illustrated in Figures 1 and 2 of the drawings.
Attached between the lower face 19 of the feed plunger 52 and the side wall of the bore 15 at a point above a radial passageway 31 which penetrates the pump cylinder 13 is an axial bellows 64. The axial bellows 64 is shown in an extended state in Figure 8 and in a collapsed state in Figure 9 and serves to provide the feed chamber, the feed plunger 52 forming the finger displaceable member of the feed chamber. The axial bellows 64 and the feed plunger are inseparably united in a liquid tight fashion~ This bellows thus serves the same function as the cavity defined by the bore 15 and the liquid-tight fit-ting axial piston 14 of the embodiment shown in Figures 1 and 2 of the drawings, but with advantage it provides, as shown in the embodiment illustrated in Figures 8 and 9 for a virtually friction free sliding movement of axial piston 1~ and feed plunger 52 within bore 15, and freedom from leakageO
Fitted within the lower hollow end of piston 14 and penetrating a~ial plunger ~2 is a spigot valve 42 with associated seating 43, the spigot valve being biased towards the seating by spring ~4 also housed within the lower end of piston 14. The spigot valve constitutes the discharge valve having a moveable member.

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The stalk 45 of spigot valve 42 normally extends below~the lower end of piston 1~ as shown in the drawings, the stalk being in axial alignment with upper end 46 o~
spacer 200 The upper end of discharge outlet 16 in piston 14 can be closed by an actuator button (not shown).
The pump cylinder 13 also houses a piston return spring 18 abutting lower end 19 of piston 14 and upper -~ace o~
apertured spacer 20 and situated within the axial bellows 64.
This spring biases the piston upwards as shown in Figure 8 of the drawings 90 that piston shoulder 21 abuts the apertured pl~te ll when the pump i9 in the non-actuating condition shown in Figure 8. The same spring also biases the cylindrical bellows 64 ~owards its fully open position. The spacer 20 separates the pump cylinder 13 from a non-return ~eed valve assembly 22.
The radial passageways 31 of pump cylinder 13 connect both the lo~er end of bore 15 and the interior o~
the axial bellows 64 with an annular chamber 32 bounded by outer body 10 and pump cylinder 13, thereby providing a conduit ior liquid product to pass between the feed chamber (i.e.
a~ial bellows 64) and the annular chamber 32.
Thc annular chamber 32 houses a loose fitting annular disc 33a which is biased against a spring 36 (the resilient means), itsel~ housed in upper part 41 o~ the cylindrical 2S cavity enclosed between outer hody 10 and pump cylinder 13 together with apertured plate ll o - 29 - / ' : , , ,: , , , ~.
.
. . .
, ' - .: , . , ' ' ,~ ' Also housed within this upper part 41 and extending int.o annular chamber 32-- is an annular bellows 65 (the discharge chamber), the upper portion o~ whlch (within the upper part 41) is o~ smaller diameter than the lower portion (wi.thin the chamber 32). This annular bellows thus appears stepped when viewed in longitudinal section as shown in Figures 8 and 9, the in-termediate face 66 bearing agai.ns-t the annular disc 33a.
~he wall. o~ outer body 10 and that of pump cylinder 13 are both per~orated with corresponding breathing channels 39 and 40, which communica~e-via the upper part 41 of annular chamber 32.
In use, the pump as illustrated in Figures 8 and 9 of the drawings is applied to the top of a container of liquid so that the non-return pressure actuable feed valve assembly is ln contact with that liquid, i~ necessary via a dip-tube (not shown).
At the ~irst downstroke of piston 14 the piston return spring 18 i~s compressed together with axial bellows 64 and air in -the axial bellows and in -the lower part of bore 15 is temporarily ~orced via radial passageways 31 into annular beilow~ 65 within annular chamber 32, and is thèn released to atmosphere, when the stalk 4S of spigot val~e ~2 is displaced by contact wi-th upper end ~6 o~ spacer 20. When piston 1~ ig released, liquid product is drawn up through ..,..~, ' ' ', '' ' S~
non-return ~ee~ valve assembly 22 into the axial bellows 64 within cylinder bore 15. This i9 a priming operation and the pump is now ready -for use.
A-t the 9 econd downstroke of the piston 14, the axial bellows 64 is compressed and the liquid wi-thin it under increasing hydrau1ic pressure is -thereby caused to flow via radial passageways 31 into the lower portion o~ the annular bellows 65 within annular chamber 32. A further increase in pressure o~ this liquid extends the lower portion of the annular bellows 65 so that its upper face 66 displaces the _ _ __ annular disc 33a against spring 36. More liquid then ~lows into the annular chamber within the lower end of the annular bellows. As annular disc 33a moves with the expanding volume o~ this lower part of the second bellows, acc~mulating energy is stored in spring 36 as it is compressed. As hydraulic pressure increases still fur~her, displacement o~
annular disc 33a continues to increase in order to accommodate liquid, until the stalk 45 o~ spigot val~e 42 contacts the upper end 46 o~ spacer 20. Continuation of the downstroke beyond this poin-t unseats the spigot valve 42 and its displacement against bias o~ spring 44 allows liquid product to pass *rom the lower end of the annular bellows 65 within the annular chamber 32 via radial passageways 31, collapsed axial bellows 64 within cylinder bore 15 and past seating 43, to discharge outlet 16 in piston 14 and finally to atmosphere via actuator button (not shown).

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As ~iquid is discharged, decompression of spring 36 forces annular disc 33ato the rest position the upper (narrower) portion of the annular bellows being extended and the lower (wider) portion being comprssed. The annular chamber 32 with its contained annular bellows is finally sealed when ~inger pressure on the pump dispenser is released, spigot valve 4Z closing and piston 14 returning to -the rest position under decompression of piston return spring l8. Simultaneously, more liquid product iY drawn into the a~ial bellows within cylinder bore 15 via non-return valve assembly 22 and the discharge and ~illing cycle can then be repea-ted.
According to the ~i~th embodiment of the invention as illustrated in Figures 10 and 11, the annular bellows having a stepped configuration with a wide diameter portion and a narrow diameter portion can be replaced with a double cylindrical bellows 65a having an outer cylindrical wall o~ similar dimensions and configuration to the lower portion illustrated in Figures 8 and 9 of the drawings but having an inner cylindrical wall o~ similar height to the outer wall.
The outer and inner walls o~ the annular bellows of the embodiment illustrated in Figures 10 and 11 thu~ lie against the respective inner and outer walls o~ the annular chamber 32-and are bridged by an annular end wall to form a sealed de~ormable compartment within the annular chamber 32 adapted .,~, .

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to receive liquid under pressure during an actuation sequence.
The double cylindrical bellows 65a constitute the discharge chamber. This latter modification to the annular bellows is illustrated in Figures 10 and 11 of the drawings which in all other respects are similar to Figures 8 and 9.
Further modi*ica-tions of the embodiments illustrated in Figures 8 to 11 of the drawings can be incorporated without substantial loss of efficiency o~ operation. For example, as illustrated in Figures 12 and 13, the axial 10- bellows 64 can be omitted and the axial plunger 52 attached to piston 14 made a liquid tight fit within cylinder bore 15 with an 0 rin~ seal 68 in the manner illustrated in Figures 1 and 2 o~ the drawings. In this example, the amlular bellows 65 can either take the stepped configuration as illustrated in Figures 8,9912 and 13 or they can take the double annular configuration as illustrated in Figures 10 and 11.
Alternatively~ as illustrated in Figures 14 and 15, the annular bellows 65 and 65a can be omitted and the annular plunger 33 made a liquid tight fit within the annular chamber 32~ for e~ample with 0 ring seals 35, in the manner illustrated in Figures 1 and 2 of the drawings.
According to the sixth embodiment of the invention as illustrated in Figures lB and 17 of the dra~ings, the pump consists of an outer body 10 containing a pump cylinr3er 13 with piston 14 and associated features generally as described with reference -to Figures 1 and 2 of the drawings.

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Pump cylinder 13 is provided with radial passageways 31 which co~municate discharge chamber 32 and the-bore 15 o~ pump cylinder 13. The annular discharge chamber 32 houses a pair of annular plungers 33 and 34, with seals 35 which are urged by a pair of springs 36 and 37 (the resilient means) towards each other. Shoulders 38 on body 10 prevent the - annular plungers 33 and 34 from meeting.
~he wall of outer body 10 and that of pump cylinder 13 are both perforated with corresponding breathing channels 39 and ~0, which communicate via the upper part 41 of annular discharge chamber 32. ~his upper part 41 also houses the upper spring 36 while the corresponding lower part 41a houses the lower spring 37.
In use, the pump as illustrated i~ Figures 1~ and 17 is applied to the top of a container of liquid product so that the non-return valve assembly i9 in contact with that liquid, if necessary via a dip-tube ~not shown).
At the first downstroke of piston 14 towards the feed valve 22~ the piston return spring 18 is compressed, and when the stalk 45 of spigot valve 42 is displaced by contact with upper end 46 of spacer 20, air in bore 15 is bled via radial passageways 31, annular discharge chamber ~2 to atmosphere.
Whe~ piston 14 i9 released, liquid is drawn up through -the feed valve assembly 22 into cylinder bore 15. 'rhis i~ a priming operation and the pump is now ready for use.

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A-t the second downstroke of the piston 14, liquid within cylinder bore 15 is subjected to an increase in hydraulic pressure and it is thereby caused to ~`low via radial passageways 31 to annular discharge chamber 32 and annular plungers 33 and 3~. Further increase in pressure on this liquid displaces the annular plungers 33 and 34 away ~rom each other against their respective springs 36 and 37, so that liquid ~lows in-to the annular discharge chamber 32. As pistons 33 and 34 move apart, the volume o-~
the annular discharge chamber 32 correspondingly increases and accummulating energy i9 stored in springs 36 and 37 as they are compressed. As pressure increases still further, displacement of annular plungers 33 and 34 continues to increase in order to accommodate liquid, until the stalk 45 of spigot valve 42 contacts the upper end 46 of spacer 20.
Continuation o~ the downstroke be~ond -this point unseats the spigot valve 42 and its displacement against bias of spring 44 allows liquid to discharge -to atmosphere via discharge outlet 16 in piston 14 and actuator button (not shown).
As liquid is discharged, decompression of springs 36 and 37 forces annular plungers 33 and 34 ~owards each other to the rest position where they abut shoulders 38 on outer body 10. The annular discharge chamber 32 is ~inally sealed when finger pressure on the pump is released, the pis-ton 14 - 35 ~ /

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,.:, , returning to the rest position under decompression of piston return spring 18~ Simultaneously, more liquid prcduct is drawn into the cylinder bore 15 via non-return feed valve assembly 22 and the discharge and filling cycle can then be re~eated.
When finger pressure on the stem of piston 14 i9 released9 piston 1~ moves upwards, the stalk 45 of spigot valve 42 moves away from the associated upper end 46 of spacer 20, and spring ~4 biases the spigot valve onto its seating ~3 so halting passage of liquid past the spigot valve.
As the piston 14 returns to its rest position under decompression of piston return spring 18, more liquid product is drawn into bore 15 via non-return feed valve assembly ~2 and the discharge and filling cycle can then be repeated.
The pump according to the invention is intended to be used for dispensing liquids or gels, in particular shearable gels, from a container which pro~ides a supply of liquid or gel product external to the pump. The pump can therefore, for example, be designed for attachment to a hand held container of a si~e and capacity similar to a conventional pressurised pack or aerosol container. It is also envisaged that the pump can be readily detachable from its container so that a refill container can be fitted wh0n the original container is empty of product.

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, The liquid or gel product can be dispensed as a fine particulate spray or in any other form in which -the product i9 not finely divided, depending on the type of actua-tor buttoM which is -fitted to the pump.

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Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A finger operable pump for dispensing liquids comprising:
(a) an axially arranged feed chamber having a finger displaceable end wall, axial movement of which will vary the volume of said feed chamber, (b) a pressure actuable valve to permit entry of a liquid product from an external supply to the feed chamber, said valve and said feed chamber being so positioned that downward axial movement of the finger displaceable end wall towards said valve reduces the volume of the feed chamber and increases hydraulic pressure therewithin, and upward axial movement of the finger displaceable end wall away from said valve increases the volume of the feed chamber and reduces hydraulic pressure therewithin;
(c) an axial discharge chamber in communication with said feed chamber;
(d) a resilient means positioned co-operably with the discharge chamber for storing energy generated by the increased hydraulic pressure which results from downward movement of the finger displaceable end wall with respect to the feed chamber;

(e) a discharge conduit communicating the discharge chamber with the atmosphere exterior to the pump;
(f) valve means for releasing the energy stored in the resilient means and for conducting the liquid product from the discharge chamber to the discharge conduit, said valve means being operable to release the energy and provide a conduit for the liquid product only after the finger displaceable end wall has moved downwardly with respect to the feed chamber by a predetermined distance, the finger displaceable end wall form-ing a liquid tight seal with a side wall of the feed chamber at least until after said valve means is operated.

2. A pump as claimed in claim 1, wherein the axially arranged feed chamber is a cylinder and the finger displaceable end wall is a piston slidably positioned in the cylinder.

3. A pump as claimed in claim 1, wherein the axially arranged feed chamber is a bellows and the finger displaceable end wall is an end wall of the bellows, downward movement of said end wall reducing the axial length of the bellows towards its collapsed state, and upward movement of said end wall.
increasing axial length of the bellows towards its fully extended state.

4. The pump as claimed in claim 1 a 2 or 3, wherein the pressure actuable valve is a ball valve.

5. The pump as claimed in claim 1,2 or 35 wherein the resilient means is a coil spring.

6. The pump as claimed in claim 1, wherein the axial discharge chamber houses a plunger resiliently loaded by the resilient means.

7. The pump as claimed in claim 6, wherein the axial discharge chamber houses a second plunger in addition to the first, the second plunger being resiliently loaded by the resilient means.

8. A pump as claimed in claim 1,2 or 3, wherein the axial discharge chamber houses a bellows for containing the liquid product passing form the axially arranged feed chamber when hydraulic pressure in said feed chamber is increasing, the below being resiliently loaded by the resilient means,

9. A pump as claimed in claim 1,2 or 3, wherein the cross-sectional area of the axially arranged feed chamber is less than that of the axial discharge chamber.

10. The pump as claimed in claim 1, wherein the valve for releasing the energy stored in the resilient means is provided by a mechanically actuable valve opening axially through the finger displaceable end wall of the feed chamber, the mechanically actuable valve being so positioned as to be mechanically actuated at the termination of a downward movement of the finger displaceable end wall when the volume of the feed chamber approaches its minimum value.

11. The pump as claimed in claim 10, wherein the mechanically actuable valve is a spigot valve.

12. A pump for dispensing liquids comprising:
(a) a cylinder;
(b) a pressure actuable valve to permit entry of a liquid product to the cylinder from an external supply;
(c) a finger displaceable piston slideably positioned in the cylinder, the piston increasing hydraulic pressure in the cylinder as it moves downwardly in the cylinder toward the pressure actuable valve and reducing hydraulic pressure as it moves upwardly in the cylinder away from the pressure actuable valve;
(d) an annular discharge chamber positioned co-axially with respect to the cylinder and piston, said discharge chamber being in communication with said cylinder;

(e) a spring for storing energy generated by the increased hydraulic pressure which results from the piston sliding downwardly in the cylinder, said spring being positioned co-operably with the annular discharge chamber;
(f) a discharge conduit communicating the discharge chamber with the atmosphere exterior to the pump;
and (g) a spigot valve for releasing the energy stored in the spring and conducting the liquid product from the annular discharge chamber to the discharge conduit, said spigot valve being operable to release the energy and provide a conduit for the liquid product only after the piston has moved downwardly in the cylinder by a predetermined distance, and the piston forming a liquid tight seal with the cylinder at least until after the spigot valve is operated.
n

13. A pump for dispensing liquids comprising:
(a) an axially arranged first bellows having a sealably engaged finger displaceable end wall, axial movement of which will vary the volume of said first bellows;
(b) a pressure actuable valve to permit entry of a liquid product from an external supply to the first bellows, said valve and said first bellows being so positioned that downward axial movement of the finger displaceable wall toward the valve reduces the volume of the first bellows and increases hydraulic pressure therewithin, and upward axial movement of the finger displaceable end wall away from the valve increases the volume of the first bellows and reduces hydraulic pressure therewithin;
(c) an axial discharge chamber comprising a second bellows in communication with the first bellows, said second bellows being arranged to receive liquid product passing from the first bellows when hydraulic pressure in said first bellows is increasing;
(d) a spring for storing energy generated by the increasing hydraulic pressure which results from the finger displaceable end wall of the first bellows moving downwardly with respect to the first bellows thereby to reduce the volume of the first bellows, said spring being positioned co-operably with the second bellows so as to bias the second bellows towards its collapsed state;
(e) a discharge conduit communicating the second bellows with the atmosphere exterior to the pump;
and (f) a mechanically actuable valve opening axially through the finger displaceable end wall of the first bellows, said mechanically actuable valve being so positioned as to be mechanically actuated at the termination of a downward movement of the finger displaceable end wall of the first bellows when the volume of the first bellows is at its minimum value, thereby to reduce the energy and provide a conduit for the liquid product, the first bellows and its finger displaceable end wall forming a liquid tight seal at least until after the mechanically actuable valve is activated.